Install Java on RHEL, Rocky Linux, AlmaLinux and Fedora

Java on RHEL, Rocky Linux, AlmaLinux, CentOS Stream, Oracle Linux, and Fedora usually means OpenJDK RPMs from the distribution’s enabled repositories—free, updated through the operating system, and integrated with the alternatives system. When your release does not ship the Java major you need, add Eclipse Temurin from Adoptium or install Oracle JDK from a vendor tarball.

This guide covers OpenJDK with dnf, JRE and headless variants, Temurin on Rocky Linux 10.2, Oracle JDK from a tarball, alternatives version switching, JAVA_HOME, a compile-and-run check, update paths, and uninstall steps per method.

Tested on: Rocky Linux 10.2 (Red Quartz); OpenJDK 21.0.11 (java-21-openjdk-devel); Temurin 17.0.19 (temurin-17-jdk from Adoptium rhel/10 repository).

JDK, JRE, and package names on RHEL-family Linux

Java terminology overlaps in documentation and RPM names. The table below maps common terms to what you install on Enterprise Linux.

On RPM-family Linux, package names do not always mirror the major version number literally. Java 8 commonly uses java-1.8.0-openjdk, while newer majors use names such as java-17-openjdk and java-21-openjdk. Search the exact naming your release publishes before you install.

When you are unsure whether you need a JRE or JDK, install the JDK (java-<version>-openjdk-devel). Red Hat OpenJDK documentation recommends the JDK when you are unsure; Fedora includes OpenJDK as its default open-source Java implementation. Graphical export features in applications such as JasperReports Server can still need fonts, a browser, or other dependencies even when the Java process itself runs headless on the server.

Choose an install method

Most readers should install java-<version>-openjdk-devel from their distribution repositories when that version exists. Search the exact package naming used by your release; Java 8 commonly uses java-1.8.0-openjdk, while newer majors use names such as java-17-openjdk and java-21-openjdk. Add Temurin when dnf list available shows no matching OpenJDK package for your target major.

Prerequisites

• RHEL, Rocky Linux, AlmaLinux, CentOS Stream, Oracle Linux, or Fedora with sudo and outbound HTTPS for dnf and optional Adoptium repositories.
• Enough disk space—each full JDK is roughly 150–400 MB with dependencies.
• For Debian-family hosts, see install Java on Debian.

Refresh metadata with dnf makecache before you search or install:

sudo dnf makecache

Check whether Java is already installed:

java -version 2>&1 || echo "java: not installed"
javac -version 2>&1 || echo "javac: not installed"

Sample output when OpenJDK 21 is the active default:

openjdk version "21.0.11" 2026-04-21 LTS
OpenJDK Runtime Environment (Red_Hat-21.0.11.0.10-1) (build 21.0.11+10-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-21.0.11.0.10-1) (build 21.0.11+10-LTS, mixed mode, sharing)
javac 21.0.11

List OpenJDK packages your enabled repositories provide:

dnf list available 'java-*-openjdk*'

For a compact package-name list:

dnf repoquery --available --qf '%{name}' 'java-*-openjdk*' | sort -u

Sample output on Rocky Linux 10.2:

java-21-openjdk
java-21-openjdk-devel
java-21-openjdk-headless

If repoquery is unavailable, install the DNF plugins package your distribution documents for that release.

List installed OpenJDK packages separately to see what already owns the active alternative:

dnf list installed 'java-*-openjdk*'

On Rocky Linux 10.2 AppStream publishes OpenJDK 21 packages such as those above. RHEL 9 and compatible rebuilds may also list java-17-openjdk, java-11-openjdk, or java-1.8.0-openjdk depending on release and repository access. For broader CLI reference beyond the dnf steps below, see the Linux commands index.

Method 1: Install OpenJDK from dnf (recommended)

Install the JDK when you compile Java code or run Buildomatic-style tooling. Replace 21 with the major version your application requires and your repositories publish:

sudo dnf install -y java-21-openjdk-devel

The install completes with Complete! when dnf finishes without errors.

Verify the runtime and compiler:

java -version

Sample output:

openjdk version "21.0.11" 2026-04-21 LTS
OpenJDK Runtime Environment (Red_Hat-21.0.11.0.10-1) (build 21.0.11+10-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-21.0.11.0.10-1) (build 21.0.11+10-LTS, mixed mode, sharing)

javac -version

Sample output:

javac 21.0.11

The java-21-openjdk-devel package pulls in the matching runtime and headless libraries. JVM files land under /usr/lib/jvm/java-21-openjdk/ on the tested host.

Method 2: Install JRE or headless OpenJDK

Use a runtime-only package when you do not need javac—typical for Tomcat hosts that only execute WAR files. Prefer the JDK when you compile code or run Buildomatic-style tooling.

Install a minimal headless runtime:

sudo dnf install -y java-21-openjdk-headless

Confirm only the runtime is required before you skip -devel—tools such as Maven, Gradle, and JasperReports Server Buildomatic need a JDK with javac. Server-side Java can be headless while JasperReports still needs separate browser or font packages for graphical PDF and dashboard export.

Method 3: Install Eclipse Temurin from Adoptium

When your distribution repositories do not ship your target Java major, add the Adoptium RPM repository. Adoptium’s Linux installation docs derive the distribution segment from /etc/os-release and note that unsupported distribution and version combinations may work only on a best-effort basis.

On the tested Rocky Linux 10.2 host, the automatically derived rocky/10 path was unavailable, while the rhel/10 path worked. The repository below therefore pins the tested RHEL-compatible path:

sudo tee /etc/yum.repos.d/adoptium.repo > /dev/null <<'EOF'
[Adoptium]
name=Adoptium
baseurl=https://packages.adoptium.net/artifactory/rpm/rhel/$releasever/$basearch
enabled=1
gpgcheck=1
gpgkey=https://packages.adoptium.net/artifactory/api/gpg/key/public
EOF

On Fedora or other releases, check Adoptium’s current repository tree and supported-platform list before you copy this file. AlmaLinux and CentOS Stream hosts may need the same rhel segment override when the OS ID path does not resolve.

Refresh Adoptium metadata and list available Temurin JDK packages:

sudo dnf makecache --disablerepo='*' --enablerepo=Adoptium
dnf list available 'temurin-*-jdk'

Sample output:

temurin-11-jdk.x86_64                 11.0.31.0.0.11-0                  Adoptium
temurin-17-jdk.x86_64                 17.0.19.0.0.10-0                  Adoptium
temurin-21-jdk.x86_64                 21.0.11.0.0.10-0                  Adoptium

Install the major you need—for example Java 17 on Rocky Linux 10 when the tested AppStream repositories had no java-17-openjdk:

sudo dnf install -y temurin-17-jdk

Verify Temurin is registered and check its JVM path:

java -version
ls -ld /usr/lib/jvm/java-17-temurin-jdk

Sample output after switching the default with alternatives (see the next section):

openjdk version "17.0.19" 2026-04-21
OpenJDK Runtime Environment Temurin-17.0.19+10 (build 17.0.19+10)
OpenJDK 64-Bit Server VM Temurin-17.0.19+10 (build 17.0.19+10, mixed mode, sharing)
drwxr-xr-x. 9 root root 4096 Jul 12 11:36 /usr/lib/jvm/java-17-temurin-jdk

Fedora hosts may use the fedora Adoptium path from Adoptium Linux installation docs when rhel does not match your release.

Method 4: Install Oracle JDK from a tarball

Oracle JDK is not shipped in distribution repositories on RHEL-family Linux. Review Oracle licensing and support terms before you choose Oracle JDK for organizational deployment. Download the Linux x64 archive from Oracle Java downloads and extract it under /opt with tar:

sudo mkdir -p /opt/jdk
sudo tar -xf jdk-21_linux-x64_bin.tar.gz -C /opt/jdk

Register the binaries with alternatives—replace jdk-21 with your extracted directory name:

sudo alternatives --install /usr/bin/java java /opt/jdk/jdk-21/bin/java 2100
sudo alternatives --install /usr/bin/javac javac /opt/jdk/jdk-21/bin/javac 2100

These commands register only java and javac. A complete JDK exposes additional tools such as jar, javadoc, jshell, and keytool. Register any additional commands your workflow requires, or invoke them through $JAVA_HOME/bin to avoid mixing tools from different JDKs.

Select and verify the Oracle build:

sudo alternatives --config java
sudo alternatives --config javac
java -version
javac -version

Most open-source workloads should prefer OpenJDK or Temurin (OpenJDK install guide).

Switch between installed JDKs

Fedora and RHEL-family packaging use the alternatives system to switch installed Java implementations. When multiple JDK packages are installed, alternatives manages the /usr/bin/java and /usr/bin/javac symlinks separately—selecting Java 17 for java does not necessarily select Java 17 for javac.

List registered JVMs:

alternatives --display java | head -20

Sample output (trimmed):

link currently points to /usr/lib/jvm/java-21-openjdk/bin/java
/usr/lib/jvm/java-21-openjdk/bin/java - priority 21001110
/usr/lib/jvm/java-17-temurin-jdk/bin/java - priority 1161

Switch both runtime and compiler interactively:

sudo alternatives --config java
sudo alternatives --config javac

Verify both binaries point at the same major version:

java -version
javac -version
readlink -f "$(command -v java)"
readlink -f "$(command -v javac)"

Or set a specific path—Temurin 17 on the tested host:

sudo alternatives --set java /usr/lib/jvm/java-17-temurin-jdk/bin/java
sudo alternatives --set javac /usr/lib/jvm/java-17-temurin-jdk/bin/javac
java -version
javac -version

Return to distribution OpenJDK 21:

sudo alternatives --set java /usr/lib/jvm/java-21-openjdk/bin/java
sudo alternatives --set javac /usr/lib/jvm/java-21-openjdk/bin/javac
java -version

To return the runtime and compiler to automatic priority-based selection, run:

sudo alternatives --auto java
sudo alternatives --auto javac

Then verify both versions with java -version and javac -version.

Set JAVA_HOME

Build tools and application servers expect JAVA_HOME to point at the JVM root, not the bin/java file. Resolve the active binary with command -v and readlink before you export the path:

readlink -f "$(command -v java)"

Sample output:

/usr/lib/jvm/java-21-openjdk/bin/java

Derive and export JAVA_HOME:

export JAVA_HOME="$(dirname "$(dirname "$(readlink -f "$(command -v java)")")")"
echo "$JAVA_HOME"

Sample output:

/usr/lib/jvm/java-21-openjdk

Persist JAVA_HOME for login shells:

echo "export JAVA_HOME=$JAVA_HOME" | sudo tee /etc/profile.d/java.sh
sudo chmod 644 /etc/profile.d/java.sh

This stores a fixed JDK path. Changing the java alternative later does not automatically update JAVA_HOME—update the profile file or service configuration when you switch the required JDK. That distinction matters for Tomcat, Maven, Gradle, and JasperReports Buildomatic.

Files under /etc/profile.d/ are loaded by compatible login or interactive shells. A systemd service does not normally source them. For a service, add the variable to its unit or drop-in:

[Service]
Environment="JAVA_HOME=/usr/lib/jvm/java-21-openjdk"

Reload the unit configuration after you edit the file:

sudo systemctl daemon-reload
sudo systemctl restart SERVICE

Replace SERVICE with your unit name, such as tomcat. Some applications also support EnvironmentFile= when they already read a dedicated environment file.

Confirm the directory exists before you hard-code a path in unit files:

ls -ld /usr/lib/jvm/java-21-openjdk*

Verify Java with a sample program

Compile and run a short program to confirm javac and java use the same JDK:

cat > /tmp/Hello.java <<'EOF'
public class Hello {
    public static void main(String[] args) {
        System.out.println("Hello, Java on Rocky Linux");
    }
}
EOF
javac /tmp/Hello.java
java -cp /tmp Hello

Sample output:

Hello, Java on Rocky Linux

Remove the test files when you are done:

rm -f /tmp/Hello.java /tmp/Hello.class

Update Java packages

Distribution OpenJDK packages update with normal dnf maintenance:

sudo dnf upgrade 'java-*-openjdk*'

Temurin packages update from the Adoptium repository when it stays enabled:

sudo dnf upgrade 'temurin-*'

Package updates can refresh alternatives registrations or priorities. After updating systems with multiple JDKs, verify the selected runtime and compiler:

java -version
javac -version
alternatives --display java | head -5

Uninstall Java

OpenJDK packages

List installed OpenJDK RPMs with rpm:

rpm -qa | grep openjdk

Remove the development and runtime packages you no longer need. Preview the transaction first:

sudo dnf remove --assumeno java-21-openjdk-devel java-21-openjdk java-21-openjdk-headless

Review the dependency list, then run the actual removal:

sudo dnf remove java-21-openjdk-devel java-21-openjdk java-21-openjdk-headless

After removal, confirm no stale alternative or profile entry remains:

alternatives --display java
java -version

Remove or update /etc/profile.d/java.sh if it still points at the deleted JDK.

Temurin

sudo dnf remove -y temurin-17-jdk
sudo rm -f /etc/yum.repos.d/adoptium.repo
sudo dnf makecache

Oracle tarball

Remove the alternatives entries before you delete the extracted directory:

sudo alternatives --remove java /opt/jdk/jdk-21/bin/java
sudo alternatives --remove javac /opt/jdk/jdk-21/bin/javac
sudo rm -rf /opt/jdk/jdk-21

Replace jdk-21 with your exact extracted directory. Delete any /etc/profile.d/java.sh snippet that referenced that path.

Troubleshooting

Summary

Install Java on RHEL-family Linux with sudo dnf install java-<version>-openjdk-devel when your distribution repositories ship your target major. Use java-<version>-openjdk-headless for runtime-only hosts when you are certain no compiler is required. Add Eclipse Temurin from Adoptium when the distribution lacks the version you need, or install Oracle JDK from a tarball when your organization requires it. Switch defaults with alternatives for both java and javac, set JAVA_HOME for login shells and systemd separately, verify with java -version and a javac compile test, and preview package removal with dnf remove --assumeno before you uninstall.

Official references:

• OpenJDK install guide
• Adoptium Linux installation
• Red Hat OpenJDK documentation
• Oracle Java downloads.